BRANDING: Business Cards

I have sent off to Moo.com for a set of 10 free business cards as before I pay for any amount I'd like to see what they look like. Here are the design I used, again my number is blurred:

The back of these cards just feature my logo, I got 5 printed with the logo on white and 5 in a dark grey with a white logo, I think I'll prefer the colour ones, but I thought as they were free samples it was worth trying both out.